Indicating vent plug for electric storage batteries



p 9, 1952 c. KELLER 2,610,221

INDICATING VENT PLUG FOR ELECTRIC STORAGE BATTERIES Filed March 25, 1949 v z] 1 1 Z0 -EIG. 6. INVENTOR.

(fin/315s L. K5440 ATTORNEYS.

Patented Sept. 9, 1952 no STATES I? INDIGATINGYEN'EPLUG FOR ELECTRICII l t STORKGE' BATTERIES V n l 2 filial-1e51 Kellenxwfimetkai 111;, assignor'to Thr? Richardson: Company, ltockland ohioaaicnrpo ration of Ohiow 1 t.

Application Maren 25, 1949; sen-aim.- 83,4161": 55:01am; (01. lee-182.):

My'inventionhasto do with" theprovisioi iiof' vent" plugs for, electric" storage batteries, which plugs will, withoutiremovasl}; indieatewhether or not"the electrolyteis below a" predetermined level;

and hence whether oii not thecell' oftlie storage battery requires the: addition J of water:

Various types of indicating vent -plugs+-liave=-- hitherto been-proposed "whiizh -incorporate faz fibat member for" the purpose' described Hbwever;

these" structures have been complicated and ex= pensive in manufacture; have involved partsor structures projecting above-"the normal. level 0f the" topmi the? vent" plug so as to interfere with the use or" appearance- 0f the storagebattery; OFYIBNE incorporated moving parts so related as. to he liable tofailure due'-t0--sticliing', jamming or 'theslikee l l i indication Jot the electrolytes eve-11 eveniin .1dim1ri light, 1 and whichzis operation;

Th'eseendcother 'objects ofstl'ie inventionliwhichs will fbe?set:fimthvhereinafterrorswillar be apparent? troublefiree and l certajnu 1m toaone skilledfinithel artrupon "reading thimspeci v fication, I accomplish-by: that construction; and. arrangementwof parts oflwhich $1 shall now deiseribean exemplaryi'embodiments Referencedsmade tonthe accompanying drawingslwherein:

Figures li iS'Ja" top plansview: of myt improved-ovent. plug withtthevindicator actuated bYElBQ- 1 trolyteat normal level Figure 2 is; a sectionala View thereofltakenzalons, the seotionsliner 2r-2 oi -Figured, partslof ia ston age.a battery cell. cover. being-l shown in: dotted lines' a t Figure 3is.a to p. plan view the. .fioat in the nomindicating'position" Eigure. 4. is a sectional lview taken. along, the. section line 4-4"of Figure 3'," and Ish'owing. parts.

offa storage hattery cell cover in dottedlines.

Figure 511s an explodedview offtlielseveral' partsofii'my.indlcatingvent plug.

dflmy. stnucturelwithm Figure 6 ma bottom.plan View o-fth' topudisc FigureTis atop plan view Qfftli'e floafimember taken alongj the line"F F'OLFigureBIJ Figure' 8"is a'top iantiew otthg noayelmentfl of, my structure, taken salongjjtl'ie liire8+8f of structure. comprises essentialijthieecharts l which may be separately "fabri'catedand" tlien 2; 7 a a combined into a? unitary 'structurei These partsfl are illustrated in an exploded iew in- There isa bodyfelement having" an emarged an 35 11 threaded portion II: for: engagement" in' the" The interior of" the body member is; hollow asfshown; but ai continuationof :th'e do:wnward tubular extension IZr projects upwardly Withjn i About? this upwardif? the. hollow bodrasat' l4; extension there" is at hollow annular space [56 and. gas" venttopenings" l Bi and" l Tare formedfin' the: shoulder" 13" aIidwOnnecting with thelioilowT annular space. The" downward" tubular projection hasa bore -orljcentraljopening lflfiofia, dens sired diameter," While. the" upperlextenlsi'on' of fthe' Y same. tubular element has a; bore: I.9*ofjlarge1 i diameter; there being; aishouldjen 20i1ocatedjbfe The outersurfaceof the portion I0 provides a grasping surface rwh'er eby'th'e Vent: plujg niayi be screwedinto or unscrewed from the: fillenf openingQin the cell cover; .7 and this Louter surf ace?" may be. knurledlor formed intb some convenient and. J decorative polygonal "shape tor more" ready? grasping.

The body element may he formed;-.,by-fmbming; j

of any" suitable" acid resistantipla stic' material? :bility .of the signalois not dependent uponthe" transmission ofHg'httIiroughf the bodymem'ber.

Hence; while" the body'member"maybemade of transparent; plastic? if; desired; it may" also? be made ofopaqueplastitrin' any 'color; or of such" materials as' Hard rubber composition:

It will; be noted also'ithat a; shouldei zlhi's formed" on" the outer surface of the? upwardly projecting, part" l4"0f tlieftubular extension;

My structure alsoincludes afloat!- member which; as indicated'inFiguresfi ands; is'famold' ed structure comprisingan'upper"disc elementiif of'a SiZeJtO'fitfinSide the grippingi po rtio n"lo oi my bodyelement; Int'egra1"with"the upperdisc portion thereisjadownwardly dependin t ibulan portion 23having an? internal" -diarneter capable offittingi over? theupper end of the upwardly;

extendingtubular partil l 0f thebodyflandfcomk ing to restagainst tneshouldei- 2 I The enema-ea 2 I will thus" suppo tthefdisc' portion-of theta pf member substantiallyat: tlie level of f 3 will be evident from the assembled views, Figures 2 and 4. Since the downward tubular extension 23 of the cap member isthin, it may be reinforced, as indicated in Figure 6, by rib elements The cap element will be formed from transparent or translucent plastic since one of its functions is to afford a view of the float member hereinafter described. Any suitable acid resistant transparent or translucent plastic may be employed, and its chemical composition is not a limitation upon the invention.

The third element of my structure is a hollow substantially cylindrical body 25 constituting a float. This may be made in a variety of ways. It is within the scope of my invention to make it by cutting to the desired length a piece of acid resistant plastic tubing and fitting both ends of the tubing with plastic plugs which are cemented in place with a suitable cement for the plastic in, an air-tight fashion so as to .entrap air in the hollow interior of the tube. Another and preferable mode of manufactureis to form by injection molding or otherwise a cylindrical plastic body 25 having an integral bottom .26. Then a cap element 21 for the hollow cylindrical body may be formed. of suitable plastic or other. 1 material by molding, stamping,,.cutting or the like. This cap element will have a lower portion 28 shaped to fit within the top of the hollow cylindrical body 25. Above this there will .bea flange 29 of a diameter larger than the external diameter of the hollow cylindrical body. This cap element may be placed in position as shown in Figure 5, and held in place by a press flt, or by cementing, or both. An indicia element 3!! of any desired shape may be incorporated in the top portion of the cap element. This may be done in various ways. A stamped element of other plastic may be incorporated in the cap element during molding, or groovesmay be molded in the cap element which arethen filled with a substance of contrasting color. The float element is made of acid resistant material; but it need v not be transparent or translucent unless desired.

The cap member of the float is. preferably made of White or light colored plastic or else the indicia element is made light in color. to contrast with a. darker color of the cap element itself and to give proper visibility. The visual indication provided by my indicating ventplug is the ap pearance of the cap member of the float and its indicia adjacent the disc portion 22 of 'thetop element, of my plug.

The body 25 of the float element is made of a size to Slide easily within the bore l8 of the lower depending portion of the .tubular extension l2 of the body element. The periphery and size of the top portion 29 of the float, being as.

aforesaid, of larger diameter, is shaped to have a sliding flt in the enlarged bore [9 of the upopenings l6 andll.

wardly projecting portion Id of the tubular extension of the body. This provides a double bearing for the float in its sliding movements as hereinafter more. fully explained.

The assembly of the. three essential parts of,

my structure will be clear from Figures 2 and In these figures my vent plug structure is shown screwed into place in the ent opening of a storage battery cell cover 3|. When the level of the electrolyte 32 is low, as shown in Figure 4, the

cylindrical body 25 of the float occupies its low--v ermost position, and the. enlarged flange 29 at its upper end rests against the interior shoulder 20 of the tubular extension to limit the down-.

ward motion of the float as shown. When the electrolyte is higher, it will cause the float to rise. During its rising movement the float has a double bearing to prevent cooking and sticking. Bearing is provided not only by the engagement of the tubular body 25 in the lower and smaller bore l8 of the tubular extension, but also by the engagement of the periphery of the top flange 29 of the float in the upper and larger bore 19 of the tubular extension. In its extreme upward position, as shown in Figure 2, the upper flange 29 of the float may come above the upper extension 14 of the tubular element of the body; but as soon as the level of the electrolyte 32 falls, the double bearing referred to above will become effective. 7

With the electrolyte in its highest position, as shown inFigure 2, the upper portion 29 of the float 25 will be located against or closely adjacent to the transparent or translucent disc portion 22 of the top element of my vent plug and will be clearly visible therethrough. When the level of the electrolyte is low as in Figure 4, the top portion 29 of the float will be substantially separated from the disc portion 22 of my vent plug, and the indicia 30 will be less visible, or in a dim light invisible. Thus a positive indication of theelectrolyte level is provided'so that the user of the storage battery, by glancing at its vent plug, may

determine whether the various cells need filling without removing the vent plugs.

It will be noted further that the downwar tubular extension 23 of the cap ortop member of my vent plug engage the upward extension l4 7 of the tubular element of the body and closes ofi a chamber in which the float operates.

annular space l5 may serve as a trap for electro-- lyte entrained in the escaping gases; and this electrolyte canrun back into the cell through the Any entrained electrolyte collecting in the annular space I5 is kept separated, as will be evident, from the chamber within the vent plug inwhich the float member slides; and this serves to minimize the sticking from this cause. The sliding fit of the float member in the two bores 18 and I9 is relatively loose, and will-permit the es cape of air or gas from the chamber in which 7 the float slides. Nevertheless, the bearing of the body of the float element in the downward tubular extension [2 is such as to prevent enough cocking to permit the flange portion 29 of the float to engage above the upper edge of the upper tubular extension M; or this element may be taper-bored at itsjtop; or the element l4 may be prolonged upwardly to meet the disc portion 22.

The top or cap element of my structure may be held in place in any way desired. The disc portion 22 may have a press flt in the annulus I I] or the tubular portion 23; may have a press fit in the upper end of the upper tubular extension M, or both, and either or both of these joints may be be cemented as desired. 1,

Modifications may be'made in my invention without departing from the spirit of it. Having thus described my invention in an exemplary Gases 'coming off from the electrolyte during the operembodiment, what I claim as new and desire to secure by Letters Patent is:

1. In an indicating vent plug a hollow body having a portion for engagement in the filler opening of a storage battery cell cover, a downwardly depending hollow tubular part on said portion, a float journaled for axial movement in said hollow tubular part, and a cap for said hollow body formed of material pervious to light through which the upper end of said float may become visible as it approaches said cap, said tubular part being of lesser external diameter than said hollow body, leaving a shoulder therebetween, said cap and said shoulder being perforated for the venting of gas, said tubular part having an upward extension within said hollow body, and said cap having a disc portion for closing the top of said hollow body and a depending tubular extension coacting with the upward tubular extension aforementioned, closing off within said hollow body a chamber containing a portion at least of said float, the perforations in said shoulder being located outside of said closed chamber whereby the gas being vented passes around said closed chamber out of contact with said float.

2. The structure claimed in claim 1 wherein the tubular part of said hollow body has a bore for accepting said float in its downwardly extending portion and a bore of larger diameter in its upwardly extending portion, and wherein said float has an upper flange of a diameter to slide within said upper bore but larger than the diameter of said lower bore whereby said float is retained in said body.

3. The structure claimed in claim 1 wherein the tubular part of said hollow body has a bore for accepting said float in its downwardly extending portion and a bore of larger diameter in its upwardly extending portion and wherein said float has an upper flange of a diameter to slide within said upper bore but larger than the diameter of said lower bore whereby said float is retained in said body, and wherein said float has a sliding hearing as to its body in said lower bore and a sliding bearing as to its flange in said upper bore.

4. The structure claimed in claim 1 wherein the tubular part of said hollow body has a bore for accepting said float in its downwardly extending portion and a bore of larger diameter in its upwardly extending portion, and wherein said float has an upper flange of a diameter to slide within said upper bore but larger than the diameter of said lower bore whereby said float is retained in said body, and wherein said float has a sliding bearing as to its body in said lower bore and a sliding bearing as to its flange in said upper bore, and wherein said float is an elongated tubular member having closures at its upper and lower ends entrapping air within.

5. The structure claimed in claim 1 wherein the tubular part of said hollow body has a bore for accepting said float in its downwardly extending portion and a bore of larger diameter in its upwardly extending portion, and wherein said float has an upper flange of a diameter to slide within said upper bore but larger than the diameter of said lower bore whereby said float is retained in said body, and wherein said float has a sliding bearing as to its body in said lower bore and a sliding bearing as to its flange in said upper bore, and wherein said float is an elongated tubular member having closures at its upper and lower ends entrapping air within, and wherein the said upper closure is a member comprising said flange and visible indicia incorporated in said flange.

CHARLES L. KELLER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,491,143 Kerr Apr. 22, 1924 1,508,829 Woodbridge Sept. 16,, 1924 1,525,985 Feldkamp Feb. 10, 1925 1,703,233 Hall et a1 Feb. 26, 1929 2,400,228 Franz et a1. May 14, 1946 2,484,163 Goshefi Oct. 11, 1949 2,512,757 Westall June 27, 1950 FOREIGN PATENTS Number Country Date 594,413 Great Britain Feb. 18, 1943 

